diff --git a/clang-tools-extra/pseudo/fuzzer/Fuzzer.cpp b/clang-tools-extra/pseudo/fuzzer/Fuzzer.cpp
--- a/clang-tools-extra/pseudo/fuzzer/Fuzzer.cpp
+++ b/clang-tools-extra/pseudo/fuzzer/Fuzzer.cpp
@@ -9,9 +9,9 @@
 #include "clang-pseudo/DirectiveTree.h"
 #include "clang-pseudo/Forest.h"
 #include "clang-pseudo/GLR.h"
-#include "clang-pseudo/Grammar.h"
-#include "clang-pseudo/LRTable.h"
 #include "clang-pseudo/Token.h"
+#include "clang-pseudo/grammar/Grammar.h"
+#include "clang-pseudo/grammar/LRTable.h"
 #include "clang/Basic/LangOptions.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Support/MemoryBuffer.h"
diff --git a/clang-tools-extra/pseudo/gen/Main.cpp b/clang-tools-extra/pseudo/gen/Main.cpp
--- a/clang-tools-extra/pseudo/gen/Main.cpp
+++ b/clang-tools-extra/pseudo/gen/Main.cpp
@@ -12,7 +12,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "clang-pseudo/Grammar.h"
+#include "clang-pseudo/grammar/Grammar.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/FileSystem.h"
diff --git a/clang-tools-extra/pseudo/include/clang-pseudo/Forest.h b/clang-tools-extra/pseudo/include/clang-pseudo/Forest.h
--- a/clang-tools-extra/pseudo/include/clang-pseudo/Forest.h
+++ b/clang-tools-extra/pseudo/include/clang-pseudo/Forest.h
@@ -20,8 +20,8 @@
 #ifndef CLANG_PSEUDO_FOREST_H
 #define CLANG_PSEUDO_FOREST_H
 
-#include "clang-pseudo/Grammar.h"
 #include "clang-pseudo/Token.h"
+#include "clang-pseudo/grammar/Grammar.h"
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/Support/Allocator.h"
diff --git a/clang-tools-extra/pseudo/include/clang-pseudo/GLR.h b/clang-tools-extra/pseudo/include/clang-pseudo/GLR.h
--- a/clang-tools-extra/pseudo/include/clang-pseudo/GLR.h
+++ b/clang-tools-extra/pseudo/include/clang-pseudo/GLR.h
@@ -30,8 +30,8 @@
 #define CLANG_PSEUDO_GLR_H
 
 #include "clang-pseudo/Forest.h"
-#include "clang-pseudo/Grammar.h"
-#include "clang-pseudo/LRTable.h"
+#include "clang-pseudo/grammar/Grammar.h"
+#include "clang-pseudo/grammar/LRTable.h"
 #include "llvm/Support/Allocator.h"
 #include <vector>
 
diff --git a/clang-tools-extra/pseudo/include/clang-pseudo/cxx/CXX.h b/clang-tools-extra/pseudo/include/clang-pseudo/cxx/CXX.h
--- a/clang-tools-extra/pseudo/include/clang-pseudo/cxx/CXX.h
+++ b/clang-tools-extra/pseudo/include/clang-pseudo/cxx/CXX.h
@@ -23,7 +23,7 @@
 #ifndef CLANG_PSEUDO_CXX_CXX_H
 #define CLANG_PSEUDO_CXX_CXX_H
 
-#include "clang-pseudo/Grammar.h"
+#include "clang-pseudo/grammar/Grammar.h"
 
 namespace clang {
 namespace pseudo {
diff --git a/clang-tools-extra/pseudo/include/clang-pseudo/Grammar.h b/clang-tools-extra/pseudo/include/clang-pseudo/grammar/Grammar.h
rename from clang-tools-extra/pseudo/include/clang-pseudo/Grammar.h
rename to clang-tools-extra/pseudo/include/clang-pseudo/grammar/Grammar.h
--- a/clang-tools-extra/pseudo/include/clang-pseudo/Grammar.h
+++ b/clang-tools-extra/pseudo/include/clang-pseudo/grammar/Grammar.h
@@ -49,8 +49,8 @@
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef CLANG_PSEUDO_GRAMMAR_H
-#define CLANG_PSEUDO_GRAMMAR_H
+#ifndef CLANG_PSEUDO_GRAMMAR_GRAMMAR_H
+#define CLANG_PSEUDO_GRAMMAR_GRAMMAR_H
 
 #include "clang/Basic/TokenKinds.h"
 #include "llvm/ADT/ArrayRef.h"
@@ -221,4 +221,4 @@
 } // namespace pseudo
 } // namespace clang
 
-#endif // CLANG_PSEUDO_GRAMMAR_H
+#endif // CLANG_PSEUDO_GRAMMAR_GRAMMAR_H
diff --git a/clang-tools-extra/pseudo/include/clang-pseudo/LRGraph.h b/clang-tools-extra/pseudo/include/clang-pseudo/grammar/LRGraph.h
rename from clang-tools-extra/pseudo/include/clang-pseudo/LRGraph.h
rename to clang-tools-extra/pseudo/include/clang-pseudo/grammar/LRGraph.h
--- a/clang-tools-extra/pseudo/include/clang-pseudo/LRGraph.h
+++ b/clang-tools-extra/pseudo/include/clang-pseudo/grammar/LRGraph.h
@@ -28,10 +28,10 @@
 //  in making decisions.
 //===----------------------------------------------------------------------===//
 
-#ifndef CLANG_PSEUDO_LRGRAPH_H
-#define CLANG_PSEUDO_LRGRAPH_H
+#ifndef CLANG_PSEUDO_GRAMMAR_LRGRAPH_H
+#define CLANG_PSEUDO_GRAMMAR_LRGRAPH_H
 
-#include "clang-pseudo/Grammar.h"
+#include "clang-pseudo/grammar/Grammar.h"
 #include "llvm/ADT/Hashing.h"
 #include <vector>
 
@@ -178,4 +178,4 @@
 };
 } // namespace llvm
 
-#endif // CLANG_PSEUDO_LRGRAPH_H
+#endif // CLANG_PSEUDO_GRAMMAR_LRGRAPH_H
diff --git a/clang-tools-extra/pseudo/include/clang-pseudo/LRTable.h b/clang-tools-extra/pseudo/include/clang-pseudo/grammar/LRTable.h
rename from clang-tools-extra/pseudo/include/clang-pseudo/LRTable.h
rename to clang-tools-extra/pseudo/include/clang-pseudo/grammar/LRTable.h
--- a/clang-tools-extra/pseudo/include/clang-pseudo/LRTable.h
+++ b/clang-tools-extra/pseudo/include/clang-pseudo/grammar/LRTable.h
@@ -33,10 +33,10 @@
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef CLANG_PSEUDO_LRTABLE_H
-#define CLANG_PSEUDO_LRTABLE_H
+#ifndef CLANG_PSEUDO_GRAMMAR_LRTABLE_H
+#define CLANG_PSEUDO_GRAMMAR_LRTABLE_H
 
-#include "clang-pseudo/Grammar.h"
+#include "clang-pseudo/grammar/Grammar.h"
 #include "llvm/ADT/ArrayRef.h"
 #include <cstdint>
 #include <vector>
@@ -189,4 +189,4 @@
 } // namespace pseudo
 } // namespace clang
 
-#endif // CLANG_PSEUDO_LRTABLE_H
+#endif // CLANG_PSEUDO_GRAMMAR_LRTABLE_H
diff --git a/clang-tools-extra/pseudo/lib/GLR.cpp b/clang-tools-extra/pseudo/lib/GLR.cpp
--- a/clang-tools-extra/pseudo/lib/GLR.cpp
+++ b/clang-tools-extra/pseudo/lib/GLR.cpp
@@ -7,8 +7,8 @@
 //===----------------------------------------------------------------------===//
 
 #include "clang-pseudo/GLR.h"
-#include "clang-pseudo/Grammar.h"
-#include "clang-pseudo/LRTable.h"
+#include "clang-pseudo/grammar/Grammar.h"
+#include "clang-pseudo/grammar/LRTable.h"
 #include "clang/Basic/TokenKinds.h"
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/STLExtras.h"
diff --git a/clang-tools-extra/pseudo/lib/cxx/CXX.cpp b/clang-tools-extra/pseudo/lib/cxx/CXX.cpp
--- a/clang-tools-extra/pseudo/lib/cxx/CXX.cpp
+++ b/clang-tools-extra/pseudo/lib/cxx/CXX.cpp
@@ -7,7 +7,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "clang-pseudo/cxx/CXX.h"
-#include "clang-pseudo/LRTable.h"
+#include "clang-pseudo/grammar/LRTable.h"
 
 namespace clang {
 namespace pseudo {
diff --git a/clang-tools-extra/pseudo/lib/grammar/Grammar.cpp b/clang-tools-extra/pseudo/lib/grammar/Grammar.cpp
--- a/clang-tools-extra/pseudo/lib/grammar/Grammar.cpp
+++ b/clang-tools-extra/pseudo/lib/grammar/Grammar.cpp
@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "clang-pseudo/Grammar.h"
+#include "clang-pseudo/grammar/Grammar.h"
 #include "clang/Basic/TokenKinds.h"
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/STLExtras.h"
diff --git a/clang-tools-extra/pseudo/lib/grammar/GrammarBNF.cpp b/clang-tools-extra/pseudo/lib/grammar/GrammarBNF.cpp
--- a/clang-tools-extra/pseudo/lib/grammar/GrammarBNF.cpp
+++ b/clang-tools-extra/pseudo/lib/grammar/GrammarBNF.cpp
@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "clang-pseudo/Grammar.h"
+#include "clang-pseudo/grammar/Grammar.h"
 #include "clang/Basic/TokenKinds.h"
 #include "llvm/ADT/DenseSet.h"
 #include "llvm/ADT/STLExtras.h"
diff --git a/clang-tools-extra/pseudo/lib/grammar/LRGraph.cpp b/clang-tools-extra/pseudo/lib/grammar/LRGraph.cpp
--- a/clang-tools-extra/pseudo/lib/grammar/LRGraph.cpp
+++ b/clang-tools-extra/pseudo/lib/grammar/LRGraph.cpp
@@ -6,8 +6,8 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "clang-pseudo/LRGraph.h"
-#include "clang-pseudo/Grammar.h"
+#include "clang-pseudo/grammar/LRGraph.h"
+#include "clang-pseudo/grammar/Grammar.h"
 #include "llvm/ADT/DenseSet.h"
 #include "llvm/ADT/Hashing.h"
 #include "llvm/ADT/STLExtras.h"
diff --git a/clang-tools-extra/pseudo/lib/grammar/LRTable.cpp b/clang-tools-extra/pseudo/lib/grammar/LRTable.cpp
--- a/clang-tools-extra/pseudo/lib/grammar/LRTable.cpp
+++ b/clang-tools-extra/pseudo/lib/grammar/LRTable.cpp
@@ -6,8 +6,8 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "clang-pseudo/LRTable.h"
-#include "clang-pseudo/Grammar.h"
+#include "clang-pseudo/grammar/LRTable.h"
+#include "clang-pseudo/grammar/Grammar.h"
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/Support/ErrorHandling.h"
diff --git a/clang-tools-extra/pseudo/lib/grammar/LRTableBuild.cpp b/clang-tools-extra/pseudo/lib/grammar/LRTableBuild.cpp
--- a/clang-tools-extra/pseudo/lib/grammar/LRTableBuild.cpp
+++ b/clang-tools-extra/pseudo/lib/grammar/LRTableBuild.cpp
@@ -6,9 +6,9 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "clang-pseudo/Grammar.h"
-#include "clang-pseudo/LRGraph.h"
-#include "clang-pseudo/LRTable.h"
+#include "clang-pseudo/grammar/Grammar.h"
+#include "clang-pseudo/grammar/LRGraph.h"
+#include "clang-pseudo/grammar/LRTable.h"
 #include "clang/Basic/TokenKinds.h"
 #include <cstdint>
 
diff --git a/clang-tools-extra/pseudo/tool/ClangPseudo.cpp b/clang-tools-extra/pseudo/tool/ClangPseudo.cpp
--- a/clang-tools-extra/pseudo/tool/ClangPseudo.cpp
+++ b/clang-tools-extra/pseudo/tool/ClangPseudo.cpp
@@ -9,10 +9,10 @@
 #include "clang-pseudo/Bracket.h"
 #include "clang-pseudo/DirectiveTree.h"
 #include "clang-pseudo/GLR.h"
-#include "clang-pseudo/Grammar.h"
-#include "clang-pseudo/LRGraph.h"
-#include "clang-pseudo/LRTable.h"
 #include "clang-pseudo/Token.h"
+#include "clang-pseudo/grammar/Grammar.h"
+#include "clang-pseudo/grammar/LRGraph.h"
+#include "clang-pseudo/grammar/LRTable.h"
 #include "clang/Basic/LangOptions.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/Support/CommandLine.h"
diff --git a/clang-tools-extra/pseudo/unittests/GLRTest.cpp b/clang-tools-extra/pseudo/unittests/GLRTest.cpp
--- a/clang-tools-extra/pseudo/unittests/GLRTest.cpp
+++ b/clang-tools-extra/pseudo/unittests/GLRTest.cpp
@@ -7,7 +7,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "clang-pseudo/GLR.h"
-#include "clang-pseudo/Grammar.h"
+#include "clang-pseudo/grammar/Grammar.h"
 #include "clang-pseudo/Token.h"
 #include "clang/Basic/LangOptions.h"
 #include "clang/Basic/TokenKinds.h"
diff --git a/clang-tools-extra/pseudo/unittests/GrammarTest.cpp b/clang-tools-extra/pseudo/unittests/GrammarTest.cpp
--- a/clang-tools-extra/pseudo/unittests/GrammarTest.cpp
+++ b/clang-tools-extra/pseudo/unittests/GrammarTest.cpp
@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "clang-pseudo/Grammar.h"
+#include "clang-pseudo/grammar/Grammar.h"
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"
 #include <memory>
diff --git a/clang-tools-extra/pseudo/unittests/LRTableTest.cpp b/clang-tools-extra/pseudo/unittests/LRTableTest.cpp
--- a/clang-tools-extra/pseudo/unittests/LRTableTest.cpp
+++ b/clang-tools-extra/pseudo/unittests/LRTableTest.cpp
@@ -6,8 +6,8 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "clang-pseudo/LRTable.h"
-#include "clang-pseudo/Grammar.h"
+#include "clang-pseudo/grammar/LRTable.h"
+#include "clang-pseudo/grammar/Grammar.h"
 #include "clang/Basic/TokenKinds.h"
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"